La Rochelle put Pau to the sword and Castres also enhanced their chances of reaching the play-offs with a win in Bordeaux.
Toulon may have been at a numerical disadvantage for most of the second half but they still managed to defeat Top 14 leaders Toulouse.
Bristol Bears and Northampton Saints were no match for La Rochelle and Clermont in the European Challenge Cup quarter-finals.
Toulouse are now unbeaten in 14 Top 14 matches after grinding it out at La Rochelle, while Racing 92 got the better of Bordeaux.
There were big wins for 2017-18 Top 14 finalists Castres and Montpellier on Saturday, with Benjamin Urdapilleta inspiring.
Toulouse's lead in the Top 14 table is down to a solitary point after Clermont Auvergne thrashed Grenoble. Lyon, meanwhile, lost at home.
Zack Holmes scored 15 points as Toulouse extended their lead at the Top 14 summit, while Stade Francais boosted their play-off hopes.
Racing 92 ran out of time in their defeat to Toulouse, while La Rochelle survived a Top14 scare against lowly Grenoble.
Clermont had not been beaten since October, but they were brought back down to earth by Top 14 champions Castres.
For the second time in two days, a side racked up a century of points in the Challenge Cup as Bristol Bears routed Enisei...
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Zebre led at half-time of their European Challenge Cup match at La Rochelle, but the hosts fought back in stunning fashion on Friday.
Clermont Auvergne hammered fellow title hopefuls La Rochelle, who had won 10 of their previous 11 matches.
The battle between top and bottom in the Top 14 table stayed true to form, Clermont running out comfortable winners on the road.
Stade Francais moved up to fifth in the table as Toulon and Racing 92 ran out convincing winners in Saturday's Top 14 action.
La Rochelle's perfect record in the Challenge Cup was ended by Bristol, but Clermont Auvergne claimed a fourth win out of four.
Montpellier's late rally did not deny Top 14 leaders Clermont Auvergne a 28-23 victory, while Guilhem Guirado scored a try in Toulon's win.